Economists Want to Know How Climate Change Raises Prices

Climate change inflation: Economists quantify warming’s $2.9 trillion price surge

Muhammad Asghar | GlobalBeat

Harvard economists released the first global measurement linking rising temperatures to consumer price increases across 147 countries since 1990.

The study found climate change added 1.5 percentage points to annual inflation rates worldwide between 2021 and 2023, equivalent to $2.9 trillion in hidden costs.

Food prices bore the heaviest impact. Maize costs jumped 21 percent above baseline projections, while wheat prices surged 19 percent higher than they would have without warming trends. The research team tracked 90,000 monthly price observations across consumer goods, isolating temperature shocks from other economic factors.

“Climate change isn’t a future problem for central banks. It’s happening now in every supermarket aisle,” said lead author Maximilian Kotz during a press briefing at Harvard Kennedy School. The team’s data shows inflation accelerated fastest in countries near the equator, where agricultural systems face the steepest temperature increases.

The study arrives as grocery prices remain 25 percent above 2020 levels in most developed economies. Central bankers have struggled to explain persistent inflation that traditional monetary tools failed to tame. Federal Reserve chair Jerome Powell acknowledged in March that “something beyond our standard models” kept prices elevated despite aggressive rate hikes.

Kotz and his co-authors isolated climate impacts by comparing price movements in months with unusual heat or rainfall against long-term averages. They controlled for oil prices, labor costs, and currency fluctuations. The methodology revealed temperature spikes above historical norms drove immediate price increases within 30 days, primarily through agricultural channels.

European Central Bank president Christine Lagarde told reporters the findings “demand a fundamental rethink” of inflation forecasting models. The ECB currently projects 2.1 percent inflation for 2026 but excludes climate variables from its calculations. Lagarde said the bank would review whether to incorporate temperature data into future projections.

Developing nations faced disproportionate impacts. Countries in sub-Saharan Africa experienced 3.2 percent additional annual inflation from climate effects, compared to 0.9 percent in North America. The disparity stems from heavier reliance on rain-fed agriculture and limited storage infrastructure that magnifies harvest shortfalls.

Bangladesh central bank governor Ahsan H. Mansur described the research as “alarming validation” of what policymakers suspected but couldn’t prove. His country saw rice prices spike 34 percent during 2023 heat waves, forcing the government to release strategic reserves. Mansur said the bank now considers extreme weather forecasts when setting interest rates.

Food companies already factor warming into pricing decisions. Unilever chief financial officer Graeme Pitkethly told investors the company adds “climate risk premiums” to long-term contracts for agricultural commodities. Nestlé increased coffee prices 15 percent last year, citing Brazilian drought conditions that reduced bean yields.

Insurance data supports the economists’ findings. Swiss Re reported weather-related crop insurance claims rose 350 percent between 2011 and 2023, with payouts increasingly tied to heat damage rather than traditional flood or storm losses. The trend pushes up food production costs that get passed to consumers.

The research undercuts arguments that inflation spikes resulted solely from pandemic stimulus or supply chain disruptions. Price increases began accelerating in 2021, before Russia’s invasion of Ukraine, and continued through 2023 despite falling energy costs. The persistence matches climate impact patterns rather than traditional business cycle dynamics.

Central banks lack tools to combat climate-driven inflation. Interest rate hikes cannot increase crop yields or build irrigation systems. “We’re using 20th century monetary policy to fight 21st century weather,” said former Bank of England policymaker Willem Buiter. He advocates separating climate inflation from demand-driven price increases when setting rates.

Some institutions adapt faster than others. The Reserve Bank of India now publishes quarterly “climate inflation monitors” tracking how monsoon patterns affect food prices. Chile’s central bank includes glacier melt data in agricultural yield projections. These innovations remain isolated rather than standard practice.

Background

Climate economics emerged as a discipline after 2006’s Stern Review quantified warming’s economic costs. Early models focused on long-term growth impacts rather than short-term price effects. The field gained urgency after 2018 when extreme weather events caused $160 billion in damages worldwide, prompting insurers to reprice risk assessments.

Traditional inflation models assume price stability returns once temporary shocks pass. They treat weather as random noise averaging to zero over time. This assumption broke down as temperatures rose systematically above historical ranges every year since 2015. Agricultural economists warned since 2018 that climate change created a “new normal” of persistent supply disruptions.

What’s Next

The Federal Reserve Board meets July 29 to review whether adding climate variables to their dual mandate of price stability and employment. Staff economists prepared briefing papers on Harvard’s methodology ahead of the meeting. A decision to incorporate temperature data would mark the biggest change to Fed forecasting since adopting inflation targeting in 2012.

Global food prices will test these findings this summer as El Niño conditions, combined with record ocean temperatures, threaten grain harvests across multiple continents. If inflation accelerates again despite cooling economies, central banks may need to acknowledge that traditional demand management cannot address supply-side climate impacts.